X-Ray Spectroscopy of Stars
... In cooler stars of spectral classes F to M, magnetic coronae, overall analogous to the solar corona, are at the origin of X-rays, enriched by flares in which unstable magnetic fields reconnect and release enormous amounts of energy in a matter of minutes to hours. The presence of coronae in these st ...
... In cooler stars of spectral classes F to M, magnetic coronae, overall analogous to the solar corona, are at the origin of X-rays, enriched by flares in which unstable magnetic fields reconnect and release enormous amounts of energy in a matter of minutes to hours. The presence of coronae in these st ...
radiation and matter interaction in strong magnetic field of accreting
... Study of quantum processes in extreme conditions helps to understand extreme astrophysical objects and vice versa our knowledge about extreme astrophysical objects allow us to check physics inaccessible at terrestrial laboratories. In this thesis I will focus on the effects of strong magnetic fields ...
... Study of quantum processes in extreme conditions helps to understand extreme astrophysical objects and vice versa our knowledge about extreme astrophysical objects allow us to check physics inaccessible at terrestrial laboratories. In this thesis I will focus on the effects of strong magnetic fields ...
l~ JHd 111
... Dwarf novae are sm all brothers of the X-ray binaries: an extended red star delivers gaseous material towards the seeond eomponent, a white dwarf. The material arrives at quite a high velocity, aeeeierated by the gravity of the white dwarf, and does normally not hit the surfaee of the white dwarf im ...
... Dwarf novae are sm all brothers of the X-ray binaries: an extended red star delivers gaseous material towards the seeond eomponent, a white dwarf. The material arrives at quite a high velocity, aeeeierated by the gravity of the white dwarf, and does normally not hit the surfaee of the white dwarf im ...
Surface temperature distribution and absorption features in Isolated
... the equation of state (EoS) P = P (ρ), if the medium is barotrope. It is determined by the model adopted to describe the matter inside the star. This system of differential equations is solved imposing the boundary conditions ρ(0) = ρc and P (R? ) = 0. Once the NS radius R? is fixed, the solution pr ...
... the equation of state (EoS) P = P (ρ), if the medium is barotrope. It is determined by the model adopted to describe the matter inside the star. This system of differential equations is solved imposing the boundary conditions ρ(0) = ρc and P (R? ) = 0. Once the NS radius R? is fixed, the solution pr ...
A STRONGLY MAGNETIZED PULSAR WITHIN THE GRASP OF THE MILKY... SUPERMASSIVE BLACK HOLE Rea ,
... might have left behind a young neutron star traveling deep into Sgr A∗ ’s gravitational potential. On 2013 April 25, a short X-ray burst was observed from the direction of the Galactic center. With a series of observations with the Chandra and the Swift satellites, we pinpoint the associated magneta ...
... might have left behind a young neutron star traveling deep into Sgr A∗ ’s gravitational potential. On 2013 April 25, a short X-ray burst was observed from the direction of the Galactic center. With a series of observations with the Chandra and the Swift satellites, we pinpoint the associated magneta ...
Chandra
... energy spectral signatures of the wind. Therefore, in order to model the observed spectrum, Hillier et al. calculated x-ray opacity in the wind from atmospheric models. They assumed x-ray emissivity scaled like density squared multiplied by a constant filling factor and used a slightly modified ,6-v ...
... energy spectral signatures of the wind. Therefore, in order to model the observed spectrum, Hillier et al. calculated x-ray opacity in the wind from atmospheric models. They assumed x-ray emissivity scaled like density squared multiplied by a constant filling factor and used a slightly modified ,6-v ...
Magnetic susceptibility, magnetization, magnetic moment and
... state of the interstellar medium (ISM) in star-forming dwarf galaxies (DGs) are obtained from observed emission line spectra from their nebular components – gaseous nebulae or nebulae surrounding the compact star-forming (SF) region (see the textbooks of Dopita & Sutherland 2003; Osterbrock & Ferlan ...
... state of the interstellar medium (ISM) in star-forming dwarf galaxies (DGs) are obtained from observed emission line spectra from their nebular components – gaseous nebulae or nebulae surrounding the compact star-forming (SF) region (see the textbooks of Dopita & Sutherland 2003; Osterbrock & Ferlan ...
110 - Institute for Astronomy
... We explore the infrared M band (4.7 µm) spectrum of the class I protostar L1489 IRS in the Taurus Molecular Cloud. This is the highest resolution wide coverage spectrum at this wavelength of a low mass protostar observed to date (R =25,000; ∆v =12 km s−1 ). A large number of narrow absorption lines ...
... We explore the infrared M band (4.7 µm) spectrum of the class I protostar L1489 IRS in the Taurus Molecular Cloud. This is the highest resolution wide coverage spectrum at this wavelength of a low mass protostar observed to date (R =25,000; ∆v =12 km s−1 ). A large number of narrow absorption lines ...
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... in the same model). If we assume that the Gaussian component is the result of an expanding source that originated at the onset of the major outburst, that is about 13 days before our observations, and that the expansion velocity of the jet is constant, the derived velocity, taking into account the s ...
... in the same model). If we assume that the Gaussian component is the result of an expanding source that originated at the onset of the major outburst, that is about 13 days before our observations, and that the expansion velocity of the jet is constant, the derived velocity, taking into account the s ...
The Milky Way-Pulsars and Isolated Neutron Stars
... on old V-2 (captured in Germany after the World War II) and Aerobee rockets, they were the first who detected X-rays from the very hot gas in the solar corona. However, the intensity of this radiation was found to be a factor 106 lower than that measured at optical wavelengths. In the late 1 X-rays ...
... on old V-2 (captured in Germany after the World War II) and Aerobee rockets, they were the first who detected X-rays from the very hot gas in the solar corona. However, the intensity of this radiation was found to be a factor 106 lower than that measured at optical wavelengths. In the late 1 X-rays ...
The keV–TeV connection in gamma-ray binaries
... The gamma-ray emission from astrophysical sources is arguably different from the emission in the rest of the electromagnetic spectrum because it cannot be generated by hot matter. High energy gamma radiation is therefore an indication that non-thermal processes, which are able to concentrate a large ...
... The gamma-ray emission from astrophysical sources is arguably different from the emission in the rest of the electromagnetic spectrum because it cannot be generated by hot matter. High energy gamma radiation is therefore an indication that non-thermal processes, which are able to concentrate a large ...
Phenomenon of total external reflection of x rays
... surfaces of ideal crystals because, due to reconstruction, their atomic structure may be characterized by a scale much greater than the interatomic distances. Clearly, the future developments and applications of x-ray optics largely depend on whether it will be possible to eliminate surface irregula ...
... surfaces of ideal crystals because, due to reconstruction, their atomic structure may be characterized by a scale much greater than the interatomic distances. Clearly, the future developments and applications of x-ray optics largely depend on whether it will be possible to eliminate surface irregula ...
ertan et al 11cesme
... For Tp = 100 K, the Lx cutoff puts an upper limit to the observable periods of AXP/SGRs. For the sources with weaker magnetic dipole fields, rin comes out of the light cylinder earlier than it does for the sources with stronger dipole fields. After this point, P remains almost constant because of d ...
... For Tp = 100 K, the Lx cutoff puts an upper limit to the observable periods of AXP/SGRs. For the sources with weaker magnetic dipole fields, rin comes out of the light cylinder earlier than it does for the sources with stronger dipole fields. After this point, P remains almost constant because of d ...
SGR 1900+14
... Radiate covering most of the electromagnetic spectrum Rotate with periods that span five decades (ms to a few hours). Are powered by their own rotational energy, residual surface heat or accretion Live tens of millions of years ...
... Radiate covering most of the electromagnetic spectrum Rotate with periods that span five decades (ms to a few hours). Are powered by their own rotational energy, residual surface heat or accretion Live tens of millions of years ...
Is $^ 6$ Li in metal-poor halo stars produced in situ by solar
... production of 6 Li by stellar flares during the main sequence. It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields ...
... production of 6 Li by stellar flares during the main sequence. It has been known for many years that the chromospheric and coronal activities of dwarf stars are closely related to their rotation (Kraft 1967). This relationship results from the generation and amplification of surface magnetic fields ...
Clumpy wind accretion in supergiant neutron star high mass X
... X-ray radiation to be compared with observations of isolated OB supergiants and massive stars in SGXBs (see, e.g., Puls et al. 2008). More recent findings seem to suggest that clumps might likely be limited to a density ratio of ∼10 compared to the surrounding medium and a lateral extent of the orde ...
... X-ray radiation to be compared with observations of isolated OB supergiants and massive stars in SGXBs (see, e.g., Puls et al. 2008). More recent findings seem to suggest that clumps might likely be limited to a density ratio of ∼10 compared to the surrounding medium and a lateral extent of the orde ...
ASTRONOMY AND ASTROPHYSICS The 10–200µm spectral
... with a Hubble constant H0 = 75 km s−1 Mpc−1 . It was classified by Mushotzky (1982) as a narrow-line X-ray galaxy (NLXG) due to its high X-ray luminosity, L(2–10 keV) ∼ 7 × 108 L , typical of low-luminosity Seyfert 1 galaxies, but with narrow (FWHM < 200 km s−1 ) emission lines, more typical of Sey ...
... with a Hubble constant H0 = 75 km s−1 Mpc−1 . It was classified by Mushotzky (1982) as a narrow-line X-ray galaxy (NLXG) due to its high X-ray luminosity, L(2–10 keV) ∼ 7 × 108 L , typical of low-luminosity Seyfert 1 galaxies, but with narrow (FWHM < 200 km s−1 ) emission lines, more typical of Sey ...
Astronomy Astrophysics A VLT/FLAMES survey for massive binaries in Westerlund 1 &
... spectra of W239 to search for the signature of a companion(s), noting that the shorter wavelength data were of too low S/N and resolution to permit such an analysis and the longer wavelength data are dominated by a near-IR excess due to hot dust (Sects. 2.2 and 2.3). The FLAMES spectra cover Pa11-16 ...
... spectra of W239 to search for the signature of a companion(s), noting that the shorter wavelength data were of too low S/N and resolution to permit such an analysis and the longer wavelength data are dominated by a near-IR excess due to hot dust (Sects. 2.2 and 2.3). The FLAMES spectra cover Pa11-16 ...
0004-637X 778 2 119
... torques (Rea et al. 2013). This can actually be taken as an upper limit to the strength of the dipole field. If the neutron star is evolving with an active fallback disk, the dipole field strength that can produce the properties of this source could be in the (1–2) × 1012 G range on the surface of t ...
... torques (Rea et al. 2013). This can actually be taken as an upper limit to the strength of the dipole field. If the neutron star is evolving with an active fallback disk, the dipole field strength that can produce the properties of this source could be in the (1–2) × 1012 G range on the surface of t ...
Summary of Talks at Growing Black Holes 2004 in Garching
... Statistics : Overall fraction of AGN in the sample >50% for nearby L* galaxies at low redshift. Fraction declines toward higher z (because of increasing stellar contamination in the 3 arcsec fiber?) The AGNs are similar to the red galaxies in terms of structural properties. In terms of stellar p ...
... Statistics : Overall fraction of AGN in the sample >50% for nearby L* galaxies at low redshift. Fraction declines toward higher z (because of increasing stellar contamination in the 3 arcsec fiber?) The AGNs are similar to the red galaxies in terms of structural properties. In terms of stellar p ...
Article PDF - IOPscience
... understanding of high-mass X-ray binary formation and evolution. By combining binary population synthesis and detailed mass-transfer models, however, we show that the binary parameters of M82 X-2 are not surprising provided non-conservative mass transfer is allowed. Specifically, the donor-mass lower ...
... understanding of high-mass X-ray binary formation and evolution. By combining binary population synthesis and detailed mass-transfer models, however, we show that the binary parameters of M82 X-2 are not surprising provided non-conservative mass transfer is allowed. Specifically, the donor-mass lower ...
GRB EXPERIMENT
... • To explain SGRs and AXPs, however, B must be greater than the quantum critical value 4.4 x 1013 G, where the energy between electron Landau levels equals their rest mass • Some AXPs and SGRs require B~1015 Gauss, so these magnetars have the strongest cosmic magnetic fields that we know of in the u ...
... • To explain SGRs and AXPs, however, B must be greater than the quantum critical value 4.4 x 1013 G, where the energy between electron Landau levels equals their rest mass • Some AXPs and SGRs require B~1015 Gauss, so these magnetars have the strongest cosmic magnetic fields that we know of in the u ...
Cosmological dynamics with non-minimally coupled scalar field and
... example from the quantum field theory in curved spacetime. f ( R) theories are also widely used as an alternative explanation of the dark energy phenomena which places them amongst the most popular and widely explored alternative theories of gravity. Most of the studies on f ( R) theories though are ...
... example from the quantum field theory in curved spacetime. f ( R) theories are also widely used as an alternative explanation of the dark energy phenomena which places them amongst the most popular and widely explored alternative theories of gravity. Most of the studies on f ( R) theories though are ...
The Historical X-ray Transient KY TrA in quiescence
... improved position of α = 15:28:16.97 and δ = −61:52:57.8. In 2007 June we obtained I, R and V images, where the counterpart seems to be double indicating the presence of an interloper at ∼1.4 arcsec NW. After separating the contribution of KY TrA we calculate I = 21.47 ± 0.09, R = 22.3 ± 0.1 and V = ...
... improved position of α = 15:28:16.97 and δ = −61:52:57.8. In 2007 June we obtained I, R and V images, where the counterpart seems to be double indicating the presence of an interloper at ∼1.4 arcsec NW. After separating the contribution of KY TrA we calculate I = 21.47 ± 0.09, R = 22.3 ± 0.1 and V = ...
X-ray astronomy
X-ray astronomy is an observational branch of astronomy which deals with the study of X-ray observation and detection from astronomical objects. X-radiation is absorbed by the Earth's atmosphere, so instruments to detect X-rays must be taken to high altitude by balloons, sounding rockets, and satellites. X-ray astronomy is the space science related to a type of space telescope that can see farther than standard light-absorption telescopes, such as the Mauna Kea Observatories, via x-ray radiation.X-ray emission is expected from astronomical objects that contain extremely hot gasses at temperatures from about a million kelvin (K) to hundreds of millions of kelvin (MK). Although X-rays have been observed emanating from the Sun since the 1940s, the discovery in 1962 of the first cosmic X-ray source was a surprise. This source is called Scorpius X-1 (Sco X-1), the first X-ray source found in the constellation Scorpius. The X-ray emission of Scorpius X-1 is 10,000 times greater than its visual emission, whereas that of the Sun is about a million times less. In addition, the energy output in X-rays is 100,000 times greater than the total emission of the Sun in all wavelengths. Based on discoveries in this new field of X-ray astronomy, starting with Scorpius X-1, Riccardo Giacconi received the Nobel Prize in Physics in 2002. It is now known that such X-ray sources as Sco X-1 are compact stars, such as neutron stars or black holes. Material falling into a black hole may emit X-rays, but the black hole itself does not. The energy source for the X-ray emission is gravity. Infalling gas and dust is heated by the strong gravitational fields of these and other celestial objects.Many thousands of X-ray sources are known. In addition, the space between galaxies in galaxy clusters is filled with a very hot, but very dilute gas at a temperature between 10 and 100 megakelvins (MK). The total amount of hot gas is five to ten times the total mass in the visible galaxies.